What Is The Lowest Ideal Salinity For Healthy Fish In A FOWLR?

[JumboShrimp]

As a FOWLR— without corals (or even a CUC) to worry about— I was wondering what salinity my fish would do best at— short of 1.025? I’m not shooting for permanent hypo-salinity, of course, but would there be health advantages to 1.021 or even lower on a permanent basis? Thanks!

 

[Old Fritz]

Hard to say really as I don't believe there are any studies determining long term effects of lower levels of salinity. It might be something I'd want to try but that would be a multi-year project with a lot of variables to control for. Most stores (and the ones I worked at included) kept salinity in fish only tanks at 1.020 and there seems to be no long term effect. I've seen people with salinity down to 1.015 and keeping that long term and the fish still doing "fine" (fine is in quotations because I obviously do not have constant access to assess his tank).

If it were my tank I'd just keep it at 1.020

 

[Goodair]

1.020-1.022 is what seems to be FOWLR salinity although longterm effects is unknown.

 

[pdxmonkeyboy]

I would not keep it under .021. As others have stated, many keep Fowler tanks around here. There seems to be this popular myth that lower salinity is "easier" on fish. I have not really sought out the reason for this belief but I do know that the physiology of salt water fish retains water (because they life in an environment saltier than themselves and therefore loose water).

But on the plus side.. you can achieve the listed gallons for salt mixes if you go 1.021

 

[AquaholicAquariums]

1.021-1.022 for FOWLR. Don’t see any benefits in running it higher then that really.

 

[The Aquatic Arsenal]

I go for 1.019 personally.

 

[S2G]

I did 1.022 for a long time with puffers, eels, & an angel

Now that I think about I had green spotted puffers in 1.020

 

[Fishnut]

1.019 in my FOWLR tanks. Hermits. snails, angels, tangs, wrasses, clowns all happy and healthy

 

[IndianReefGuy]

Finally a subject I'm not clueless on.....So I've been talking to my LFS owner, super knowledgeable etc....I tested his water prior to putting his stuff in my tanks..just to gauge where he was at with Ca, Alk, ph, nitrates, and of course Salinity.
One of the things that came up in our discussion was the salinity. While my tank is constant at 1.025 his was at 1.021. He then showed me a bag with some paperwork from the same supplier that provides fish to that TV show about building tanks (I forget the name but they built a shark tank for Tracy Morgan ...) In any case the paperwork said the fish were at 1.017!!!
He then goes on to tell me that it's kept at that level to deter parasites and infections. His fish look good at the lower levels, all eating ...but..... they seem to have a harder time going from that low salinity to my tank...its takes a while for them to act normal, usually don't eat right away from me., but eventually acclimate.
Hope that helps!

 

[JumboShrimp]

Very useful information, thank you. My fish seem the same to me at 1.021 through 1.025, so currently I’m sticking in the 1.021 to 1.022 range — why spend money on salt needlessly?

 

[Thomashtom]

I Have done lower down to 1017 when dealing possible parasites problems. Parasites dont do as well in lower salinity. Otherwise 1020 is ok!

 

[Feet4Fish]

I run my Fowlr at 1.020. Have dropped it before due to suspected parasites. I also run the system at 75-76 degrees. Rationale personally is that the lower salinity allows the fish to use less of its energy for osmoregulation and can use it”s immune system and/or growth. Also the cooler water can hold a bit more dissolved oxygen. I have some big fish and a deep tank so ensuring maximum DO is important to me.

 

[Rmckoy]

A lfs told me years ago. .
They keep their salinity lower 1.020) for a few reasons
1) cost ( they were using oi purple buckets for their fish . And a reef salt for their corals and Inverts .
2) parasites
They have more time to sell them without signs of parasites .
Sadly ..... acclimating them to nsw should extend longer than a traditional drip acclimation

I remember reading something about how much salinity can fluctuate or adjust without any effects on livestock